Family doctors rounded on PM David Cameron over the “damaging, unnecessary and expensive” health reforms they argue will cause “irreparable damage to patient care and jeopardise the NHS.”

Health Secretary Andrew Lansley.

The Royal College of General Practitioners wrote to the Prime Minister stating that the Health and Social Care Bill should not be amended but scrapped altogether.

“We remain unconvinced that the Bill will improve the care and services we provide to our patients,” college chairwoman Clare Gerada said.

The college represents more than 44,000 family doctors who will find themselves at the centre of the major NHS shake-up, which hands them the lion’s share of the health budget to spend on commissioning services.

Three-quarters of the college have already stated the Bill should be withdrawn in a recent poll.

The college wrote to Health Secretary Andrew Lansley to voice members’ concerns but decided to take action after receiving his response and following the government’s tabling of amendments.

Mr Lansley said the government had been “carefully listening” to opinions about the Bill and the series of amendments would “address these remaining issues.” But Dr Gerada said the college’s position has not changed and concerns expressed when the Bill was still at its white paper stage 18 months ago have not been addressed, including the role of private companies.

She said: “Competition and the opening up of our health service to any qualified providers will lead not only to fragmentation of care, but also potentially to a two-tier system with access to care defined by a patient’s ability to pay.

“We cannot sit back. Instead, we must once again raise our concerns in the hope that the Prime Minister will halt this damaging, unnecessary and expensive reorganisation which, in our view, risks leaving the poorest and most vulnerable in society to bear the brunt.”

She added that the college could not support a Bill that would “ultimately bring about the demise of a unified national health service.”

Health Emergency campaign director John Lister reiterated demands for Mr Lansley to come clean on the government’s “risk register” on the NHS reforms compiled over a year ago.

A blog has published a leak saying the risk register included concerns of “a surge in health-care costs,” that privatisation could make the NHS “unaffordable” and that GPs lack experience and skills in managing costs if the reforms went ahead.

Mr Lister added: “For 12 whole months he has denied MPs and peers information they needed to form a proper evaluation of the Bill. He has even admitted his fears that publication could swing opinion against his unpopular and controversial proposals.

“Above all, it’s a Bill to empower the private sector, not patients or clinicians. That’s why the Bill cannot be amended. It must be defeated or withdrawn.”